Add hook for update_instance_cache_with_nw_info¶
https://blueprints.launchpad.net/nova/+spec/instance-network-info-hook
A hook of the update_instance_cache_with_nw_info call will allow hooks access to valuable network information as soon as it becomes available. This will be useful for sending this data to scripts that can make informed tweaks to the networking on hosts.
Problem description¶
Right now there is no way to hook into the updating of network info.
Usecase: * Deployer would be able to register a hook to send networking information to a script that could make informed tweaks to networking on hosts. This might include flows or QoS.
Proposed change¶
Add a hook to the update_instance_cache_with_nw_info call to allow hooks access to this information.
Alternatives¶
This information is stored in the database, and could be accessed from there. But, this would require giving access to the database to outside applications and could potentitally increase load on the database.
Data model impact¶
None
REST API impact¶
None
Security impact¶
None
Notifications impact¶
None
Other end user impact¶
None
Performance Impact¶
The new code itself will not introduce any performance impact, but due to the nature of hooks, any deployer introduced hooks could have a performance impact. It will be up to the deployer to test their hooks for performance impact.
Other deployer impact¶
This change will introduce a new location for hooks. It will not immediately effect a deployment, as new hooks would need to be introduced that would take advantage of this new hook location.
Developer impact¶
None
Implementation¶
Assignee(s)¶
- Primary assignee:
andrew-melton
- Other contributors:
None
Work Items¶
Register a new hook for update_instance_cache_with_nw_info
Dependencies¶
None
Testing¶
Unit testing to verify that you can register a hook for update_instance_cache_with_nw_info should be sufficient. The functional testing of the actual hooks should be left to the deployer.
Documentation Impact¶
If there is a list of hook locations, it will need to be updated to include this new location.
References¶
Dev docs on nova hooks: http://docs.openstack.org/developer/nova/devref/hooks.html
